A recent design trend has been the introduction of capless filler systems for vehicle fuel systems. A capless filler does away with the traditional screw-on fuel cap in favor of an automatic seal which is opened upon the insertion of the nozzle of a fuel hose from a gas station pump. A capless filler has one or more spring loaded flappers that are actuated by the insertion of a nozzle, and the flapper automatically springs back to a closed sealing position with the withdrawal of the inserted nozzle. The seal provided by the spring loaded flapper is generally tighter and more reliable than the traditional screw-on fuel cap, which is important to maintain the pressure in a vehicle fuel system, and to prevent gas fumes from escaping into the environment. FIG. 1 shows a prior art capless filler 64 mounted on the side of a vehicle 62.
Capless fillers provide several benefits to a user including reducing the chance for a gas smell on their hands, since the user simply flips open the fuel door and inserts the pump nozzle in the opening of the capless filler. Not having a twist-on/off gas cap is one less contact with a gasoline-vapor odor source, and prevents the discomfort experienced by people with arthritis or other impairments that make the act of twisting a cap awkward or painful. The possibility of a gas cap dangling and scratching the paint during fueling in eliminated, as well as the embarrassment of a forgotten gas cap left dangling or lost if forgotten by the driver after the refueling stop.
While there are many positive aspects to the use of capless fillers, existing automotive fuel additive packaging, and certain other fuel loading containers are incompatible with the capless mechanism. In general, existing fuel and additive treatment packages and fuel handling containers have external threads that get caught up in the flapper seals, and cannot be retracted after insertion into the filler neck to the gas tank. Furthermore, existing containers are not shaped or contoured for insertion and actuation of flapper seals in a vehicles capless filler system.
Thus, there exists a need for containers that are compatible with capless filler systems for manually dispensing fuel, fuel treatments, fuel additives, and engine treatments into the vehicles fuel system.